Distributed fiber optic sensors (DFOS) have become a new method for continuously monitoring infrastructure status. However, the fiber’s fragility and the installation’s complexity are some of the main drawbacks of this monitoring approach. This paper aims to overcome this limitation by embedding a fiber optic sensor into a textile for a faster and easier installation process. To demonstrate its feasibility, the smart textile was installed on a pedestrian bridge at the University of Massachusetts Lowell. In addition, dynamic strain data were collected for two different years (2021 and 2022) using Optical Frequency Domain Reflectometry (OFDR) and compared, to determine the variability of the data after one year of installation. We determined that no significant change was observed in the response pattern, and the difference between the amplitude of both datasets was 14% (one person jumping on the bridge) and 43% (two people jumping) at the first frequency band. This result shows the proposed system’s functionality after one year of installation, as well as its potential use for traffic monitoring.

Hand gesture monitoring has aroused more and more interest with the development of emerging virtual reality technologies. High precision and resolution are needed for more accurate gesture simulation. Gesture acquisition can be obtained by different sensing technologies including elastomers, mark-tracking technology, and fiber-opticbased sensors. Among these mechanisms, fiber-optic sensors have their unique advantages due to their small size and high accuracy. Fiber Bragg gratings (FBGs) based fiber-optic sensor was commonly used to monitor the bending of joints of the finger. However, FBG arrays can only measure specific points therefore the pattern design and the choice of the location around the joints could be an issue. In this paper, we reported a distributed fiber-optic sensing system. Optical Frequency Domain Reflectometry (OFDR) technology was used to realize the distributed strain monitor along the whole finger. A pattern of straight lines was evaluated on the index finger and the real-time strain change can be monitored. Through the real-time strain response, this system was able to provide accurate strain data according to different gestures of fingers.

Fiber optic sensors are useful for Structural Health Monitoring (SHM) as they can sense environmental change and can react to external stimuli such as mechanical and thermal changes. Embedding Fiber Optic Sensors (FOS) in textiles provides some rigidity to the sensing mechanism as they can be fully integrated with the structures. Additionally, textiles with fiber sensors reduce the overall installation cost. Previously reported fiber optic sensors for traffic monitoring were not fully integrated with infrastructure and some sensors were discretely placed in the structure which prevents continuous data collection process along the entire fiber optic cable. In this study, distributed fiber optic sensor embedded in smart textile with a length of about 28m is presented and installed in a pedestrian bridge located at the University of Massachusetts Lowell with the objective of detecting vibration generated by pedestrians as they walk on the bridge. This paper demonstrates the load change variations in terms of corresponding strain change using Optical Frequency Domain Reflectometry (OFDR). The length of the test was approximately 2.5 hours, and strain changes were recorded at a 30-minute interval. During the test, for minimum traffic on the bridge at the testing time, the recorded strain value was around 16.2με. For larger loads, 2 people walking on top of the textile induced a larger strain change which the record value was 371.2με. Based on the load of the bridge, strain changes results depict that higher loads results in higher strain change and vice versa. This type of distributed fiber optic sensor can be used for the application of real-time traffic monitoring as well as to continuously monitor the structure status of the infrastructure.